Federated learning is a potentially really great idea, but it's important to be upfront about its limitations. Just because I can't prove that a piece of data c

Federated learning is a potentially really great idea, but it's important to be upfront about its limitations. Just because I can't prove that a piece of data came from your device doesn't mean that a machine learned model trained on that data isn't violating your privacy. For example, say we deployed federated learning to train a predictive language model, and allowed it to learn from emails, say, inside Google. Looking at what the model predicts when you type "Here at Google our next secret project is..." could very likely reveal something they wouldn't want widely revealed.